Summary translation

Cattle is the most important livestock species in Swedish agriculture. There are 1.7 million animals providing products at a value of 15 billion SEK annually. These animals are also preserving the open landscape. Nematodes impose considerable constraints on livestock production systems and must be controlled. However, control using antiparasitic drugs is not allowed in organic farming. This usage is questionened (i.e. due to anthelmintic resistance, consumers concerns about food residuals, and effects on ecosystems) . Accordingly new non-chemical and sustainable options are required. Vaccination is the preferred option against lungworm. However, the present vaccine has considerable drawbacks. Thus, research must be directed towards the development of a multivalent vaccine based on recombinant technology. Genetic variation in the parasite population is likely to impact tarqet antigens. Therefore it is essential to: 1) establish methods to analyse population genetic diversity, 2) understand how overall genetic diversity is correlated with polymorphism in antigens involved in the development of protection.